The use of contra-rotating rotors for a compressor allows an increase in the compression rate for a given length and predetermined number of blade rows. This solution therefore allows shortening of the compressor and of the turbine engine containing the compressor; a substantial weight reduction is also achieved.
Document US20140286749 A1 discloses an axial turbine engine with a compressor formed by two contra-rotating rotors. Each rotor carries several rows of blades, the blades of the inner rotor and the blades of the outer rotor forming an alternating pattern. The inner rotor drives the outer rotor via a pinion, the rotation axis of which is oriented radially. The drive between the rotors takes place via various perpendicular shafts carrying pinions. A disengageable transmission is added on one of the shafts. This architecture allows modulation of the compression by decoupling the rotors. However the solution is complex because of the number of constituent elements. The production and maintenance costs require significant resources. Also, the compression rate remains reduced.